Well it is time I post something more detailed and hopefully instructive regarding ovulation in Boa Constrictors. The core of the matter is this; not all ovulations are created equal. There is a wide variation in how long, how obvious and how intense visually ovulations are in Boa Constrictors. I will describe with greater detail the ovulation process than I have done heretofore.

Ovulation in Boa Constrictors is the process whereby the female Boa, after breeding with the male Boa, goes through contractions forcing the fully developed ova into the oviduct for fertilization by the awaiting sperm previously deposited by the male. It is at this precise time that the female Boa becomes gravid or pregnant as the developed ova are able to be fertilized by the sperm and life begins for the tiny Boa Zygotes which will shortly become Embryos. Ovulation centers from a point about 65% of the way down the body from the head. This is at the location of the ovaries. The ovulation can spread out over as much as 25-30% of the animals overall length.

The most extreme ovulations are very obvious and simple to identify. Not so simple to photograph necessarily, but the big obvious ovulations jump right out at you. This you can attest to if you have seen it. Every year I have had several females that I identified as gravid, despite the fact that I had never observed an obvious ovulation. This happens to most breeders. For me this was because I was looking for the obvious "football" type ovulation as I had described many years ago and first published in the November 1996 issue of Reptiles Magazine. It was a long process but I have come to several additional conclusions that may help some to identify what is going on in their females.

There is more commonly a more subtle form of ovulation than the "Football" type ovulation which I have previously described in detail. This less obvious ovulation I call the "Slow Motion Ovulation", "Slow Mo O", or "SMO". The SMO does not happen in a huge flurry of contractions forcing the gigantic massive football like swelling. It is much more subtle, not even allowing the female to appear more massive than she was just prior to that process. The female is, most of the time, in a coiled position rather than the more stretched out posture seen with the football type ovulation. She does however appear very tense. This is because she is very tight going through contractions. Last year I video taped an ovulation and watched one female for 2 1/2 hours while she ovulated. This happened to be a football type, but the point I want to make is the same for either type of ovulation. I watched this female as she went through contractions. She made very deliberate movements that were reminiscent of the contractions a female goes through when giving birth. Every few minutes she would move very slightly. Very slightly. This could be at three minute intervals or ten minute lapses. This movement can also be continuous but will be very very slow. Almost imperceptible it is so slow. I challenge you next time you see a female that is ovulating, or that you think may be, to just sit down and, while motionless yourself, watch her go through this process. It was an amazing thing for me to watch. These movements are more subtle than the contractions of giving birth. The birth process is really sort of a slow motion process in and of itself. The ovulation process I have observed to really be even slower in its movements. Very interesting to watch if you have the patience to do so.

I believe that Boas typically have two distinct ovulations. I believe each ovary ovulates at different times and requires different movements to force the ova into their respective oviducts. I believe the first ovulation is always a more subtle ovulation or probably always the "Slow Motion Ovulation" without the football appearance. The second ovulation, if caught at the correct time, I believe is more often the football type ovulation but can sometimes be just as subtle as the "Slow Mo O". I have noticed a number of other things about the SMO.

The Slow Mo O can take a long time. I mean a long time. I had a Boa just last week was in the throes of the SMO all week long. (This was from March 21-27, 2007) This female was wringing herself every time I looked in on her. I kept watching, checking many times every day in case this was the build up to the football and final ovulation. The football never came. The male continued to show some half hearted interest in her during this period but eventually was observed pacing all over the cage looking for a way out. This is sometimes a telltale sign that she is no longer receptive and he has done his task completely.

The beauty of knowing that there is or can be a Slow Motion Ovulation that takes a precipitously long time, is the ease with which it can be observed and identified. If you know what to look for. This is the key. Boas are really pretty lethargic beasts. They move around very little. You can check your Boa(s) and notice many of them sitting in one position. Check them in an hour, exact same body position. Check another hour later, exact same body position. By same "body position" I don't mean the same place in the cage but the exact same position. When in the SMO, Boas keep moving. This just happens very very slowly. You may notice one day your female looking very tense. I notice this easily since I look for it now. They are normally coiled when this occurs. The male may still be working the female at this time as well. The only tricky thing is sometimes the male’s courtship will make the female move around a bit. As the courtship goes on, when I know that copulation is going on regularly, I wait to find that female in that coiled position. Not a symmetrical coil necessarily, never on top of herself either for that matter. But coiled about or in a back and forth coiled position rather than circularly. This position can sometimes be reminiscent of the movements of a Saw Scale Viper in a defensive posture, only 10,000 times slower. You may look at her and not see any movement. Check again in ten minutes. Then again in ten minutes and again, each time you will observe her "body position" to move gradually. Most of the time with a forward movement of her long body without changing where she is located in the cage. This forward locomotion is intense and deliberate seemingly with no destination in sight. Sometimes she will move to another location in the cage while doing this, but I have found most times this not to be the case. Over the period of days, of course the location of the female will obviously change. She does not stay in exactly the same spot for days. It's just that the movement that takes place extremely slowly is without any particular destination in mind.

If you touch the female during this time, you will be impressed with her rigidity and the strength that she uses to avoid being picked up if you attempt to do so. I'd just leave her alone during this time and not upset what G O D gave her the instinct to do long ago when he created Boas.

Boas have their POS or Post Ovulation Shed 16 – 20 days after the second ovulation and give birth approximately 105 days after that shed. These two fundamentals were included in detail as well as lots of other information in the Reptiles Article written long ago. A copy of the article can be viewed here if you want to see it with all the original pictures. Reptiles November 1996 Article. Or a slightly revised version is also available in The Boa Constrictor Manual:

I have not been able to draw any conclusion regarding fecundity in the Slow Motion Ovulation and the football like ovulation. Either one is fine by me. The “Football Ovulation” is still great fun to see to be sure. But the Slow Motion Ovulation or SMO is fundamentally more likely to be observed if you know what the symptoms are and watch for them diligently.

These are all the more obvious "Football" type ovulations I have always been most familiar with until now...